@mings_place
Nishi really loves puns. Specifically, Nishi likes to write words with the "wrong" kanji and confuse the heck out of our poor translators. "Cavalry battle" in 190 was one such case.
From BlueSpiderLily:
Cavalry Battle is usually written like this: 騎馬戦
But Nishi wrote this: 騎羽戦
The 馬 in the first one means horse
While 羽 in the second means feather
Both read the same - kibasen
We thought Nishi was being clever and had written it that way to imply they'd be in the air, but it looks like the game is just an in-universe historical reference. We used to be able to look ahead a bit to figure out what she meant, but since we've caught up we just have to take a shot and hope we're right.